I was a relatively early adopter, with a 2020 Spesh Levo SL. A great bike, I have upgraded a load on it, it had a new motor last summer. I hardly use it anymore and would happily sell it, however the second hand ebike market is nothing like the non ebike one I have found.
An equivalent 10k regular bike would likely sell for somewhere between 3.5 and 4k to the right buyer, the Spesh would be unlikely to go for more than 3k, due to the perception of unreliability with ebikes.
I think depreciation associated with expensive ebikes is much more akin to that associated with the likes of new car purchases. Not really a surprise, both technically complicated bits of kit where the manufacturers warranty is seen as a key peace of mind part of the purchase and hence if not present at resale the value plummets.
It has taken me a while to get my head round this and adjust my expectations.